Monitoring a flux application

Patent metadata

Field	Value
Publication number	US-12488455-B2
Application number	US-202418807656-A
Country	US
Kind code	B2
Filing date	Aug 16, 2024
Priority date	Aug 18, 2023
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

Various embodiments of the teachings herein include a method for monitoring a flux application in a soldering process. An example includes: defining flux wetting surfaces in relation to an image of an application surface; generating a thermographic recording of the application surface selectively provided with liquid flux; defining adjustment points on the application surface which can be identified on the image and on the thermographic recording; superimposing the image and the thermographic recording on the basis of the adjustment points; and comparing the position of temperature anomalies on the application surface identified by the thermographic recording with the position of the flux wetting surfaces on the image.

First claim

The invention claimed is:

1 . A method for monitoring a flux application in a soldering process, the method comprising:
defining respective locations for flux wetting surfaces in relation to an image of an application surface; generating a thermographic recording of the application surface selectively provided with liquid flux; defining adjustment points on the application surface which can be identified on the image and on the thermographic recording; superimposing the image and the thermographic recording on the basis of the adjustment points; and comparing temperature anomalies on the application surface identified by the thermographic recording with the respective locations of the flux wetting surfaces on the image.

2 . The method as claimed in claim 1 , wherein a temperature threshold value is set for the temperature anomalies.

3 . The method as claimed in claim 2 , further comprising initiating a measure for influencing the soldering process if, within a time interval after application of the flux, a temperature determined by the thermographic recording is on a flux wetting surface beyond the temperature threshold value;
wherein the measure initiated is selected from the group consisting of: applying additional flux to the flux wetting surface, and cleaning one or more flux application nozzles.

4 . The method as claimed in claim 3 , further comprising considering the temperature as a function of time.

5 . The method as claimed in claim 4 , further comprising:
recording a reference profile of a temperature-time curve a defined flux wetting surface; and comparing the reference profile with the temperature-time profile.

6 . The method as claimed in claim 5 , wherein a tolerance range 28 of the reference profile is defined, and the measure is initiated when the considered temperature-time profile is outside the tolerance range.

7 . The method as claimed in claim 3 , wherein the measure is taken when the temperature on the flux wetting surfaces exceeds the temperature threshold value.

8 . The method as claimed in claim 1 , wherein the thermographic recording comprises a plurality of such recordings within a period of time.

9 . The method as claimed in claim 1 , wherein the image comprises a photographic recording of the application surface to be observed.

Assignees

• Siemens Ag

Inventors

• Wittreich Ulrich
• Blank Rene
• Hanisch Michael
• Matiwe Marco
• Sommerfeld Dennis
• Jarchoff Kay
• Müller Bernd

Classifications

• G06T2207/30152

  Solder · CPC title

• G06T2207/30141

  Printed circuit board [PCB] · CPC title

• B23K1/203 Primary

  Fluxing, i.e. applying flux onto surfaces · CPC title

• G01J5/485

  Temperature profile · CPC title

• H05K2203/16

  Inspection; Monitoring; Aligning · CPC title